Friday, December 3, 2010

How to create a LED matrix

The Bubble Pop Electric team loves LED lights. I believe a performance outfit attracts best when it illuminates in darkness and follows the dynamic of the excited crowd. After deciding to use the Lilypad arduino, it was essential that we learn the skeletal blueprint of a LED matrix on fabric and the installation process while contemplating on the function of the arduino.

The team faced one of the greatest challenges when planning the distribution of the Lilypad's pins. Because the Lilypad needed to connect to the bubbles as well as the power source and the bluetooth, it could only provide 8 pins for our grand panel of around 50 LEDs. Our initial plan to control each LED was cancelled. Also, the price of the LED reduced the numbers for the panel. The 8 pins would have to accomodate for both column and row, meaning that the grid will eventually be 4x4. Technically, a 4x4 grid would only handle 16 LED, but to accentuate the brightness of the suit, the team decided to assign 2 LEDs to every crosspoint so that the suit will eventually carry 16x2=32 LEDs. The below picture shows what the suit with the sewn panel looks like.

The LED matrix requires tricky sewing. Using the conductive thread, the rows can't be touching the columns for a successful circuit. Ali used the sewing machine using a line of conductive thread and another line of non-conductive white thread- the rows are sewed from the surface and the columns are sewed from the inside. The suit has two layers of fabric. When sewn to the first layer, the non-conductive thread will create a buffer between the layers of the suit and prevent the columns and rows touching. It was a risky and careful undertaking. After the matrix is completed, LEDs with curled legs with bridge the column and the row to create a full circuit.